Hi Julien and Marius,

Julien Lepiller writes:

> Le 2018-11-22 14:58, Marius Bakke a écrit:
>> * gnu/packages/rust.scm (rust-1.19)[inputs]: Remove GIT.
>> (rust-1.20)[arguments]: Disable Cargo tests that require git.
>> (rust-1.26)[arguments]: Likewise.
>> ---
>>
>> Notes:
>>     Guix,
>>
>>     The Rust toolchain is very expensive to build and needs less
>> volatility.
>>
>>     So far I have only built up to Rust 1.23 with this patch.  I
>> suggest
>>     applying this on 'core-updates', and giving Rust in 'master' a
>>     git-2.19.1 input to the previous substitutes are valid again.
>>
>>     WDYT?
>
> Hi, I don't really know how our rust packages are built, but I wonder
> if they have more than the bare minimum optional features for our
> purposes (apart from 1.24 used by icecat and the latest version, we
> probably don't need to build everything)? Maybe it's worth
> investigating if that can speed up the build of the whole chain.

One thing I've been wondering about would be to remove the 'check phase
when building a rust that will be used for bootstrapping only. Since the
tests are not ran in parallel, they take a huge amount of time.

See attached patched, I'm testing it now. It's currently building
rust@1.23. WDYT?

Thanks,
Pierre